Originally, part 3 was intended to be a prequel, telling the story of the very first Purge. This idea was scrapped when Frank Grillo accepted James DeMonaco's offer to reprise the character of Sergeant Leo Barnes. The prequel idea was used for the next film in the series, The First Purge (2018).
As of this film, each Purge installment has earned more money at the box office than its predecessor. A rare feat for horror/thriller series.
Edwin Hodge's character is in all three of the Purge movies. In the first two, he was credited as Bloody Stranger. In this one, his name is revealed to be Dante Bishop.
The working title for the film was "The Purge: Assassins". It was later changed to Election Year mid-way through post production